I flip bikes on CL and have made "serviceable" wheels out of various parts of junk wheels. A good hub from this & a good rim from that and have used old spokes. I'm retired and have more time than money, BTW-

Whenever I junk a wheel, I strip the spokes IF they are stainless, a length I'm short on and look OK.
I wouldn't think about buying or selling used spokes or using non stainless.